The Spartan Lakonian blade used by the Spartan in the show.
The Xiphos, or "Penis" as some call it, is a short, double-edged blade, sometimes with an enlarged tip. Whenever a Spartan Warrior was nearing defeat, he would draw this weapon and spin it around. If the Spartan Warrior lost his main weapon, and had time, he would slowly pull it out of it's sheath, often saying a phrase equivalent to the English "Now I mean business.".